tables jumping

[Elijah]

i have a lane at our center that ater the table has Finished its cycle it starts to jump like its getting surges of power after it jumps about 3 or 4 times it stops you can hear the solinoid and hook assy engage and disengage everytime it jumps and honestly i dont even know where to start looking.

KG

[Rep]

Re: tables jumping

I dont think it's the solenoid and spotting latch ya hear. It's probably the contacts in the chassis, the table is drifting this usually happens after a spotting cycle but if it's bad enough it will after a respot also. Check your cams for gap, turn forward or back if necessary and more importantly check your braking mechanism in the table motor, that usually causes the table to drift when its worn. Replace the brushes (or whatever braking assy ya have) if its worn, and check your cams and I think you'll find your problem fixed [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[deadwood_dup1]

Re: tables jumping

If you have National Motors on your 70's check your brushes. When guys who try and cheat and put old brushes inside the motor instead of new ones, they tend to not apply as much pressure. Hence the motor will coast and opens TA to allow the contactor to open and close hence your bounceing table.

deadwood

[ewen]

Re: tables jumping

Elijah, I am guessing that you have older 82-70's that have a respot solenoid.
( Later models only use a spotting solenoid, with linkage connected to the respot hook)
You are correct about hearing the respot solenoid energizing .Your problem is caused by the table stopping a few degrees before zero, and then coasting in the reverse direction. When the table coasts far enough , the TA1 lever is riding on the high side of the TA1 cam , thus energizing the table contactor and the respot solenoid. The whole process can occur several times ,as you have noticed.
This is what I would do :
1) Use your gauge to adjust the TA1 lever. If table is still not stopping at exactly zero degrees, adjust the table cam assembly .
2) Change the chassis ( it is possible that the lower TABLE contacts ( which act as a brake ) are defective.
3) Replace the table motor. If you have National motors, this will probably be your problem.
4)Replace the table capacitors . I have had a bad capacitor which caused a coasting problem.
5)Check the table motor plug for burned pins ,or broken wires.
6)Check the wiring from the table motor plug ,to the terminal strip ( under the chassis ) and from the terminal strip to the C1 plug .
just a quick note, I do freelance pinspotter and pinsetter repair for several different centers. Most of the time, the spare motors ,and chassis' are not labeled , so it is uncertain as to whether they are defective [img]/content/btubb/images/%%GRAEMLIN_URL%%/mad.gif[/img] . I swap parts from a known working machine unless I know for sure that the spares work 100%.
Good luck, post again if you need more help.
Mark

[Louie_IV]

Re: tables jumping

I believe ewen hit it on the head. This also happens on 82-30's. About everything there is to check, ewen has already mentioned. One thing, instead of changing the whole motor, perhaps try changing just the stator with a spare or known good one. It might save you a little work. [img]/content/btubb/images/%%GRAEMLIN_URL%%/wink.gif[/img]

Louie [img]/content/btubb/images/%%GRAEMLIN_URL%%/cool.gif[/img]

[8270king]

Re: tables jumping

If you have Westinghouse combo's....there is too little mechanical resistance.....

1. Take stator and gearbox off machine.

2. Remove stator.

3. Remove side cap held on with 4 1/4x20 bolts.

4. Remove one or 2 small shims.

5. Reinstall and check for mechanical resistance (make sure it rotates freely with a small amount of drag).

6. Put assy. on machine.

JK

[TheGMan143]

Re: tables jumping

We have spotting solenoids on our '70s... most common causes of table drift were mentioned... I might add, that the LOWER contacts are the ones to check... they are the braking contacts. If you just eyeball them in the chassis (especially allen-brads), you will not be able to see them too well.

Check for a loose gearbox, too... I've seen a couple that were worn enough that they had to be moved to a sweep drive instead (less weight, less chance to drift)

AND... loose or worn brushes (as mentioned)... they provide mechanical resistance when the motor is stopped... if they're not pressing hard enough on the plate, the motor will stand a better chance of causing drift.

The TA switches should be checked, but they're rarely the cause of the problem stated... the drifting causes TA1 to energize the motor long enough to lift the table... the table starts drifting down, TA1 energizes, table goes up, drifts back down, and it starts to bounce.

What'sa matta wit you? Don't like the free fireworks show?